American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jul 1996
Pneumonia in intubated patients: role of respiratory airway care.
In order to assess potential risk factors for pneumonia within the first 8 d of ventilation, we studied 83 consecutive intubated patients undergoing continuous aspiration of subglottic secretions (CASS). Multivariate analysis showed the protective effect of antibiotic use (relative risk [RR] = 0.10; 95% confidence interval [CI] = 0.01 to 0.71), whereas failure of the CASS technique (RR = 5.29; 95% CI = 1.24 to 22.64) was associated with a greater risk of pneumonia. In addition, there was a trend toward a higher risk of pneumonia (RR = 2.57; 95% CI = 0.78 to 8.03) among patients with persistent intracuff pressures below 20 cm H2O. ⋯ When multivariate analysis was repeated in this subpopulation, failure of CASS (RR = 7.52, 95% CI = 1.48 to 38.07) and persistent intracuff pressure below 20 cm H2O (RR = 4.23, 95% CI = 1.12 to 15.92) were factors independently associated with the development of pneumonia. We conclude that leakage of colonized subglottic secretions around the cuff of the endotracheal tube is the most important risk factor for pneumonia within the first 8 d of intubation. This study confirms the importance of maintaining adequate intracuff pressure and effective aspiration of subglottic secretions in preventing pneumonia in intubated patients not receiving antibiotic treatment.
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Am. J. Respir. Crit. Care Med. · Jul 1996
Changes in the inflammatory response of the lung during acute respiratory distress syndrome: prognostic indicators.
We studied paired bronchoalveolar lavage (BAL) in patients with sepsis-associated acute respiratory distress syndrome (ARDS). Patients were evaluated at one institution and underwent bronchoscopy with BAL within 48 h of the onset of ARDS. Patients were restudied with bronchoscopy and BAL after 4 d of treatment. ⋯ In the follow-up lavage, there was a significant fall for the IL-8 concentrations for the survivors but not the nonsurvivors. We conclude that neutrophil influx in ARDS may rapidly resolve within a week of the onset of ARDS. The resolution of neutrophils was associated with a good prognosis.
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The purpose of this study was to determine whether diaphragmatic fatigue occurs after voluntary hyperpnea to task failure. Ten male subjects were asked to breathe at minute ventilation (V1) equal or slightly greater than 60% of their 12-s maximum voluntary ventilation (MVV) until task failure. Transdiaphragmatic pressure (Pdi) was measured during bilateral supramaximal stimulation of the phrenic nerves before and 10, 30, 60, and 120 min after hyperpnea. ⋯ The percentage fall in twitch Pdi after hyperpnea with the two techniques was not significantly correlated (r = 0.4). In conclusion, long-lasting contractile fatigue of the diaphragm reliably occurs after voluntary hyperpnea at levels sufficient to induce task failure. Cervical magnetic stimulation can detect diaphragmatic fatigue after a fatiguing task, but the results obtained with this technique may differ from those obtained with transcutaneous stimulation in individual subjects.